Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.
Definition of Expressivity
Medically reviewed by Dr. Otari Nergadze, Neurosurgeon | Updated: January 2026
Expressivity: The consistency of a genetic disease. For example, Marfan syndrome shows variable expressivity. Some persons with Marfan syndrome merely have long fingers and toes, and others have the full-blown disease, with dislocation of the lens and dissecting aneurysm of the aorta.